In This Topic ▼

LBitmapBase::GetPaintGamma

#include "ltwrappr.h"

L_UINT LBitmapBase::GetPaintGamma()

Gets the current gamma correction value for the class objects bitmap. This value is used in painting operations and is set by the LBitmapBase::SetPaintGamma function.

Returns

The value of the paint gamma used for painting the bitmap.

Because this is an unsigned integer, the return value is 100 times the actual gamma value. For example, 235 represents a gamma value of 2.35. Gamma can be any number greater than 0. The default value is 100.

Comments

This is the local paint gamma setting for the class object and is used when painting the bitmap.

Setting the gamma correction that is used for painting lets you adjust the displayed brightness of all images without changing the bitmap data.

Intensity values ideally follow a logarithmic progression, because the eye perceives changes in intensity as being equal when the ratio of change is equal. For example, we would see a change from 0.1 to 0.2 as being equal to a change from 0.2 to 0.4.

Gamma is a standard constant that is used to calculate the progression. For most CRTs the gamma constant is in the range of 2.2 to 2.5.

Required DLLs and Libraries

LTDIS
LTFIL
For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.

Platforms

Win32, x64.

Example

L_INT LBitmapBase__GetPaintGammaExample() 
{ 
   L_INT nRet; 
   LBitmapBase MyBitmap; 
   L_UINT uGamma; 
 
   nRet =MyBitmap.Load(MAKE_IMAGE_PATH(TEXT("image1.cmp")),24); 
   if(nRet !=SUCCESS) 
      return nRet; 
   uGamma=MyBitmap.GetPaintGamma(); 
 
   return SUCCESS; 
}